NATO beefed up security today around the village where 14 Serbian farmers were killed, as residents in shuttered houses mourned the victims of the deadliest single act of violence since peace formally came to Kosovo last month.

At the morgue in Pristina, Kosovo's capital, an Italian forensic team conducting autopsies on the farmers, who were killed Friday, said it would not finish its work before Tuesday, at the earliest. It was unclear when a funeral for the 14 victims would take place.

International officials said the slayings did not derail efforts to steer the province back to normality after more than a year of bloodshed that culminated in the mass expulsion by Serbs of the ethnic Albanian majority and NATO's 78-day bombing campaign. But new reports of ethnic violence added to the difficulties of reestablishing trust between Serbs and ethnic Albanians.

The Belgrade-based Beta news agency reported that a group of ethnic Albanians attacked Kosovo Serbian leader Momcilo Trajkovic today as he tried to prevent them from expelling Serbs from their apartments in Pristina.

NATO forces reported several violent incidents in Kosovo in recent days, including an exchange of gunfire Sunday night between a military patrol and occupants of a car in the western city of Pec. A NATO spokesman, Dutch army Maj. Jan Joosten, said the car was forced to stop and that one wounded man was taken to a Pec hospital while two others were held for questioning.

Near Istok, a town about 12 miles northwest of Pec, a group of gunmen fired at another NATO patrol Sunday afternoon, then fled with two NATO helicopters in pursuit, Joosten said. He said the search for the attackers was still underway today.